The 22-year-old actress is running behind schedule, and her handlers are concerned about getting her across town for an appearance on the "The Tonight Show with Jay Leno" to promote "The Twilight Saga: Breaking Dawn Part II." Three weeks into its release, the movie remains atop the box-office chart earning more than $255 million domestically.

Still, she wants to take time to talk about her next film, "On the Road," coming out Dec. 21.

In the movie, based on Jack Kerouac's enduring semi-autobiographical novel, Stewart plays Marylou, a free-spirited, sexually liberated young woman. She is one of the girlfriends/wives to the film's central character, Dean Moriarty (Garrett Hedlund), the magnetic but self-destructive friend of narrator Sal Paradise (Sam Riley).

Dean was based on the infamous beat-generation figure Neal Cassady, Sal on Kerouac, himself, and Marylou on LuAnne Henderson, who married Cassady in 1945 at age 15.

"It's said that she was ahead of her time," says Stewart about Marylou, who is a very different character than "Twilight's" staid Bella Swan. "But it takes a particular kind of person to live a life like that. She sort of had an unlimited empathy."

The actress has been committed to playing Marylou since before the "Twilight" mania began, having spoken to director Walter Salles ("The Motorcycle Diaries") about doing the role after he had seen her in 2007's "Into the Wild.

Advertisement

"

Financing for the film took awhile. Still, Stewart hung in there, saying she "would've signed on to the movie in any capacity. I would've done craft service."

The director and cast were certainly attractions for her, but a main draw was that Kerouac's novel "kick-started something" in her when she encountered it at 14.

"I read it at a stage of life where you realize that you can choose the people who surround you," she says. "You can fall into the habit of being comfortable.

There are people that are nice to be around, but they don't challenge you. Those are not the people I wanted in my life. I want people to throw me off a little bit so I can figure out why. After I read the book, I thought I needed to find people that I feel like I needed to chase after. And I wanted it to be hard to keep up with them. So it wasn't difficult to stay committed to the movie."

For someone who lives her life under a microscope, Stewart has reasons to be wary. Paparazzi swarm her every time she ventures out in public. Earlier this year, the actress made tabloid headlines for having an affair not with current beau and "Twilight" co-star Robert Pattinson, but with married filmmaker Rupert Sanders.

In person, the actress displays a thoughtful intelligence and makes a case that Marylou and the other female characters are not just sexual objects in the movie.

"For anyone who thinks that she is just a woman who was taken from, that's just a heavily misogynistic viewpoint," says the actress. "It's a really rare quality that makes you capable of living a really full, a really rich life."

Though "On the Road" was published in 1957, Stewart points out that the story is actually set in the late-1940s and written from a male perspective. "That's why you don't know where their heads are and where their hearts are," she says. "So it may be difficult to understand that they have the capacity to not be broken by (men).

Interestingly, Stewart thinks the women's movement has taken a step back over the years.

"People ask me why is the story so relevant if we progressed to this point - that times were so different, so conservative then," she says. "I'm not too sure about that. Maybe on the surface, but I don't think people change. Circumstances change. Human desires, things that you want out of life are always going to be pretty varied. But there'll always be a group of outsiders who don't feel that way. Once they find each other ... they make it OK to walk a different line and have different expectations of life."

The actress says although she was about the same age as Marylou was when she first agreed to play her, she wasn't ready then.

"This is a very irresponsible thing to do - I committed to a role before I thought I could play it," she acknowledges.

Thankfully, she says, the film took a while to get made.

"Marylou is not fearless - because that would be such a silly thing, and she's not a silly person," Stewart says.

"But she is so motivated and not crippled by fear in life. As a teenager that's a very difficult thing to achieve. That's something that a lot of people get when they're older."

At the time of this interview, Stewart was beginning final rounds of press for "Breaking Dawn Part II." Asked if she was relieved to be at the end of the five-film franchise, she said that would be an overstatement.

Still, the actress admitted that it weighed on her to be responsible for a character for so many years.

"Usually you look at the schedule and it will be like in two weeks that'll be a big day. For me it was like in three years that will be a big day. I would wonder, how's that going to go? So I'm incredibly relieved to have the story told."

She adds that the "Twilight" phenomenon is one that she is unlikely to experience again.

"It's weird to look up and notice that something you really care about has also affected so many other people. It multiplies. It's flammable, and that energy is what keeps you going," she says. "But that's a lot of energy to take in as well if you're not the most out-there person. It's overwhelming, but at the same time you can't start putting up walls. ... And the whole experience has definitely got me to a point that I don't want any walls up because I want to see out as well."

As far as what roles Stewart looks to do in the future, she has no plans.

"To find what really challenges you and really gets you off at such a young age is pretty (expletive) lucky. Most people spend years trying to find that and they never do," she says.

"I don't know what I want to do until it falls in my lap. ... I like big movies. I like small movies as long as there's an actual person to play at the center of it. I feel if I knew the stories that I wanted to tell before I saw them as an actor then I'd want to direct them, and I'm not there yet."